Apparatus for cutting metal



May Z8, 1946.

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Patented May 28, 1946 UNITED STATES PATENT OFFICE y Crosby Field, Brooklyn, and Gerald C. Toole, St. Albans, N. Y., assignors to Brillo Manufacturing Company, Inc., Brooklyn, N. Y., a corporation of New York e Application December 4, 1942, Serial No. 467,868

(Cl. Ztl-4.5) T

,used in series all Working successively on the 6 Claims.

The present invention is shown as embodied in a plant for grooving metal, preferably steel,

in such manner that the metal cut Vfrom the grooves shall constitute tough, elastic, longstaple filaments or fibers, of extremely minute but relatively uniform section and presenting for cutting operations other than grooving, or`

for operating on metals other than steel or for purposes other than `.producing the specific product above described.

The specific material which I prefer to employ is steel wire or rod Vmaterial of circular cross-section, such as is commonly supplied in bundle coils. Many features, even very'specic features, of the method are applicable to steel or other material in other forms, as, for instance, wires or rods or bands of metal that are of triangular, rectangular polygonal or other desired cross-section. For the preferred use and for producing the preferred fibrous or wood-like material from cylindrical drawn wire or rods of bendable diameter, the invention involves closer cooperative `relation of many novel features and arrangements.

In the present commerciall art some of the machines in general use for the above purposes consist essentially of a stationary bed over which a wire is drawn by a power-driven drum at' one end of the bed. As the Wire is drawn over the bed, it is guided and supported by tracks or grooves formed in the latter. A series of knives or cutters are arranged in tandem along the bed so as to be accurately adjustable and rigidly clamped with respect t the latter.

In the place of the stationary bed-type of apparatus, where great tension is required on the wire to overcome friction between the wire and the bed, machines of the tractor wheel type illustrated in Patents Nos. 1,608,478, 1,608,481 and same wire can be increased to almost any'desired extent without danger of breaking the wire because there is no corresponding increase of end traction requiredthereupon. f

In machines of the tractor wheel typev the` traction "of the winding reel Where the scrap -from themachines is wound may be reducedto that required to keep the wire in close frictional engagement'with the last'tractor wheel bed, and

1 this has 'preferably been regulated in the past by an automatic constant tension drive, `either through a friction clutch or a slipping belt or by electrical motorswith air electrical control system such as described in Patent No. 1,608,481.

With a single large tractor wheel from twenty tosixty ,knives have been used and in such cases itbecomes; practical to4 have one-directional operation. Ane important Vfeature iam-ultiply# ing the number of knives on `a given tractor wheel `lay in combining the wheel with means for keeping the wire at the proper tension so that vas the number of `knives was increased the wire would not slip with respect to the wheel.

VIn tractor Wheel systems in the past it has been the practice to usea relatively large number of tractor wheels, each with a limited number of knives, in reducing the wire to scrap in a single `pass through the plant. It has been discovered, however, that the number rof wheels heretofore regarded as desirable may be reduced,

- y layers -oi` of these turns.

with a consequent reduction in operating costs, by providing friction boosters in connection with each of the tractor wheels. It was found that the commonly accepted formulae for the increase of friction with the linear amount of surface covered by a wire wrapped around a wheel did not apply for more than one turn `of wire when the outer surfaces ofthe wires were subjected to such friction asis obtained by cutting It was discovered,` however, that this lack of `riction might be more than compensated for, andthe possible number of cutting knives accordingly increased, by the insertion into the system of` a powerf driven sheave-on which no cutting was done. In

order to accomplish this, mechanisms `to be dedescribed hereinafter were developedjand the sheaves of these mechanisms will be referred to hereinafter as capstans Oneadvantage of thiscapstan arrangement is that the pull on the wire ismaintained regardless of the speed at which the plant` is operated. Another advantage of this capstan arrangement lies in the fact that it isf possible to impress a given driving force upon the wire with less tension in the wire than would be possible without the capstan,l i. e., the tension necessary in the wire when it is wrapped around a simple wheel without a friction booster is greater than the tension necessary for drivingl the same wire past the same number ci cutting knives when a, friction booster is used in combination with the tractor wheel. This reduction in tension which the capstans make possible permits a much greater number of knives to cut all turns Without wire slippage than was possible in tractor wheel systems of earlier types.

An electrical booster control, which forms al part of the invention and whichwillr be described hereinafter, operating in the armature circuits CTI of some of the motors driving the tractor wheels y -drive on the wire so that the wire maybe driven past the knives without any slipping :between the wire and the tractor wheel. These electrical boosters have been combined with an 'improved type of idler construction so as to maintain constant tension in the wire during variations in the speed at which the wire is driven. The result is that the wire can be reduced to scrap in a single pass through a smaller number of wheels in series and in actual practice it has been possible to reduce the scrap wire to a segmental thickness as low as 9/1000 of an inch, thus giving a yield of above 95 per cent of the original cross-sectional area of the wire. V V

than the frictional drive between the tractor wheel and the wire. Still another object is the provision of an automatically equalized dynamic braking system wherein the plant is brought to a stop immediately and evenly upon a break anywhere in the wire being cut or upon an overload upon any motor. An additionalobject is the provision in ay plant of the above type of means whereby the various tractor wheels and friction boosters may be independently operated and adjusted either in the forward or reverse direction so that a break anywhere in the wire may easily be repaired. A further object is the provision in a plant ofthe above type of a delicate counterbalancing system wherein the tension on the wire may be very accurately adjusted, along with an electrical relay responsive to the counterbalanced system for accurately controlling electrical means for varying driving forces on the wire. Other objects will be in part pointed out as the description proceeds and will in part become apparent therefrom.

In` the accompanying drawings, in which a prey ferred embodiment for attaining the above ob- This extremely small segmental thickness has f been made possible in part by the addition of an improved yelectrical relay system which controls the tension of the wire between the fourth tractor wheel and the wind-up drum.

In commercial use in a plant embodying the present invention, it has been found, that. thefelectrical controls hereinafter described for the friction boosters and the electrical relay at the windup drum make possible the starting of the plant under full load, and that theplant can be continuously run, giving a higher yield and with fewer operators than has heretofore been possible. Plant efliciency has been increased partly because the improved control system has reduced time lost through wire breakage.

It is an object of the present invention toprof vide a device of the character described, having to a notable extent the characteristics and capabilities above set forth. A further object is the provision of apparatus for cutting metal wool from a wire in an improved manner. YAn additional object is the provision of aplant for producing metal wool whereinthe wool is cut from a wire wrapped around a relatively small number of tractor wheels,` associated with friction booster means, and to provide in such a plant an improved electrical control system. Still another object is the provision of a plant of the character above described wherein operations may be initiated under full load. A further object is the provision of a tractor wheel and associated friction booster creating a greater drag on the wire being cut jectives is set forth and in which like reference characters refer to like parts throughout the various views:

Figures 1a and lb in combination are a schematic representation of a plant embodying the invention;

Figure 22is' a perspective view of portions of one of the shaving units schematically represented in Figures la and 1b;

Figure 3 is an elevational view, with parts removed, of one of the main tractor wheels represented in Figures la and 1b;

Figure 4 is a section through a portion of the tractor wheel shown in Figure 2, taken. along the line 4-4`in the direction of the arrows;

Figure 5 is an enlarged detail of structure shown in Figure 3 showing the manner in which the shaving. knives are mounted;

Figure 6 is a perspective view, with parts broken away, of a portion cf the control mechanism associated with one` of the shaving units for maintaining the proper driving force upon the wire;

Figure? is a perspective view, with parts broken away, of a portion of the control mechanism which governs the speed at which the `wind-up drum is driven;

Figure 8 is aperspective view, withparts broken away, `of another portion of, the vcontrol mechanism by which the speed of the wind-up drum is governed;

VFigure 9 is an enlarged detail, partly in section, of an electric relay illustrated in Figure 7;

Figure 10 is aview, partlyin. section, taken along the line I-I il of Figure 9 in thed-irection of the arrows; and

Figures 11a and 11b in combi-nation represent schematically the electrical circuits whereby the plant is controlled.

Path followed by the wire a generator Y and one of the feeding capstans is mounted on the same shaft with a generator Z. The-,feed drum, snubber rolls and feeding capstans and their associated generator brakes comprsefa feeding unit which4 is not a part of the present invention, but which will be described in greater detail and claimed in the copending application of CrosbyField, filed herewith. i The wire, indicated by .W, is led from the feeding unit to the No. 1 shaving unit where it passes fifteen'times around a tractor wheel I0 and an idler wheel II. tractor wheel and idler Wheel, the wire is wrapped three times around idler I2 and idler wheel II, as illustrated, and then passes once around dancer roll |3 and a dancer roll idler I4 before going to the next shaving unit. A motor I6 is for driving tractor wheel I0. Idler |2 and dancer roll idler I4 are loosely and independently mounted for rotation about the same axis. Dancer roll I3 is carried by a dancer roll arm I5 pivotally mounted at its lower end. This lpivotally movable dancer roll aids in maintaining proper wire tension in a manner to be described more fully hereinafter.

The wire from shaving unit No. 1 proceeds to shaving unit No. 2 where it passes twenty times around a tractor wheel 20 and 'a capstan 2|. Thereafter it passes three times around capstan 2| and an idler. 22, and then once around Aa dancer roll 23 and a dancer roll idler 24 before going to the next shaving unit. Tractor wheel 20 is indicated as driven by a motor 26 andcapstan 2| is indicated as driven by a motor` 21. Idler 22 and dancer` roll idler 24 are loosely and independently mounted for rotation about the sameaxis. Dancer roll 23 is carried by a dancer roll arm 25 pivotally mounted at its lower end.

No. 3 shaving unit and No. 4 shaving unit are identical with No. 2 shaving unit, as illustrated. From No. 4 shaving unit wire W passes beneath a wind-up idler 5I to the wind-,up drum 50, driven by motor 56.

Hence it is observed that the present plant includes only four shaving units whereasin preceding plants ofth'e tractor wheel type twice this number of shaving units, or more, were common. One of the chief advantages of the power-driven capstans 2|, 3|, and 4I lies in the fact that by increasing the drive uponthe wire at each shaving unit, it becomes practicable to use a relatively largenumber of shaving knives in each unit so that the number of units may be reduced. In this connection it will be noted that idler wheel |I of the No. 1 shaving unit, which corresponds to the capstans of the otherv shaving units, is not powerdriven in the present embodiment. The reason for this is that no additional friction drive is necessary because only a relatively small surface of wire is in actual shaving contact with the shaving 'knives in this first unit. In so far as the invention is concerned, however, the No. 1 shaving unit might be identical with the other shaving units. Furthermore, although four shaving units havebeen illustrated in the present embodiment, the precise number which will be re.- quired will depend somewhat upon the diameters and compositions of the wires which are to be kfed into the plant and the size of the various tractor wheels.

An additional and important advantage resulting from the use of the power-driven capstans illustrated lies in the more accurate control that may be had over the wire resulting from `the greater amount of driving power..present in the `After thus passing around the plant. The provision' of the relatively great fric-` Structure of the shaving units Figure 2 shows a perspective view of the tractor` wheeL-capstan and someof the associated parts of the No. 2 shaving unit. `The wire W is indicated passing around wheel 20 and capstan 2|. Wheel 20 is driven by means of an electric motor, not shown, and -capstan 2| is driven by motor 21 through a reducing gear G.V On the near side of the wheel, as viewed in Figure 2, part of a semicircular frame |02 appears. This frame is concentrically mounted with respect to wheel 20 and it includes an air duct I 04'and an outer rim `which provides a support for the shaving knives indicated generally by K. This frame is shown in greater detail in Figure 3, where inlets |05 to airv duct |04 are` shown. `Figure 3 further shows theY mannerin which blades I I0 of the shaving knives are mounted in brackets |I2 upon studs ||8 carried by frame |02.

Figure 2` illustrates metal filaments F being blown away from the knives by air ducts, ina manner to be described, and being led by means of supports, ,various of which are indicated by numeral -I 03, to ai conveying means C t comprisingA a pair of belts |0I which move in the directions indicated by thearrows to carry. away` the filaments. One conveyor is provided for eachshaving unit and is so associated with the unit as to remove `the filaments as cut by the unit in long, continuous strands. On the far side of wheel 20, as illustrated in Figure 2, an air funnel, `or hood, H appears which exhausts air from` the regions around the cutting knives so as to remove metal particles, dust, smoke, and the like and to aid with the air ducts in leading the indi vidual filaments, away `from the wire being `cut. The entrance to the hood is protected by a screen, as indicated.

Figure 3 setslforth the manner in which the brackets ||2 are mounted on frame |02. VFigure 5 sets forth an enlarged detail of this arrangement wherein the individual blades I,|0 are `shown locked in brackets |I2 bymeans of set screws 4. Brackets ||2 are mounted on bracket bearings ||6 which, in` turn, are mounted upon studs II8` by a tapered bearing` arrangement. Each bracket IIB carries a threaded arm |20 `(see Fig-4 shaved may be'controlled.` Between each ofthe knives an air duct |06 carrying a nozzle |01 is positioned to aid `in removing the filaments as,

they are cut. .Thisarrangement of air ducts and cuttingknives does not form a part: of the present invention but 'is` described and.l claimed in the co-pending application of l Crosby Field, filed herewith. i

` Figure 4 is anen1ar`gedsectionalview along the-line 4--4V of Figure 2 and shows the manner:

inwhich'thesurface of wheel 20 is. grooved, "as

atII IIL, .to support the. wire being shaved.Y These grooves .are progressively shallower from left to rightso as to maintain the adjacent cut surfaces of successive loops of the wire even with one another'and thereby to compensate for the portions of wire removed as the wire progresses from oneside of the wheel to the other.

Shaving unit speed` control Figure 6 is a perspective view of a portion of the No. 2 shaving unit, taken from the opposite side to that shown in Figure 2. Much of'the actual shaving mechanism has been broken away in order to portray more clearly the control system therefor. Dancer roll I3 of the No. l shaving unit appears at thev right-hand side of Figure 6 carried by an arm I5 which is keyed to a dancer roll shaft |59. The position of dancer roll VI3 and, likewise, the position of dancer roll shaft |50, is determined by the length of the loop of wire passing around dancer roll I3. A

Dancer roll shaft |50 is `mounted in conventional bearings and carries on its end opposite to dancer roll arm I5 a double lever |52. Lever |52 is pinned to double links |54, which include adjustment screws |56, and each in turn is connectedV to one of the counterbalancing segment weights |58, |59, |60 and ISI. These weights areY keyed to a shaft |62 so that all segment weights thereupon move together. Shaft |62 is mounted in bearings in such manner that the number of segment weights thereupon may easily befchanged. `A clamp |64v secures the end of a sprocket chain |56 to segment weight |l59'so that the chain passes under the segment weight in contact with its Ycurved surfaceand around a sprocket |68 to a bar |16. By carrying sprocket chain it around the curved surface inthis manner, the lever arm formed between the sprocket chain and shaft |62 remains constant inlength regardless of the precise position of segment weight |59.

A pair of sprocket chains |12 and I1'3`are secured to the ends of bar |1 and are passed respectively around sprockets |14 and |115, carried by shaft |16, to support weights indicated at |11. The suspension of weights |11 is such that-the number of weights may be adjusted. Shaft |16 is mounted in conventional bearings andits lefthandend, as viewed in Figure 6, carries-a sprocket |18. An endless sprocket-chain |80 passes-about sprocket |18 and a sprocket |82!l keyed-onthe control'shaft of a rheostat |8fi. A rheostatarm |86 is also keyed to the control sha-ft of the' rheostat and rotates with the movement ofv sprocketIZ. If the'speed of the wire through the No. 1 shaving unit is slightly less than its speed throughv the No. 2 shaving unit, dancer roll I3 and dancer roll arm I5 tend to move clockwise, asV viewed `in Figure 6, to maintain constant wire tension. Such movement swings double lever |52 lclockwise and, in` turn, through links |54, moves the segment weights in a counterclockwise'direction and hence pulls upon sprocket `chain |566. The:-pull upon chain |66 induces clockwise movement-of shaft |16 and also Aclockwise movement of the control shaft of rheostat |84 vby means of endless sprocket chain |86. Clockwise movementof -the control shaft of rheostat |84 inserts additional resistance into the electrical circuit through the rheostat. This electrical circuit includes the Yeld.l of a booster generator which supplies powerto the motors for the tractor wheel and capstan "of the No. 2 shaving-unit. Increased resistancein rheostatl |84, 'l'.herefore,l decreases thepower sup,-

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plied tothe No. 2 shaving. unit in a 'mannerto be described in greater detail hereinafter. An increase inV wire speed through the No. 1 shaving unit over wire speed through the No. 2 shaving unit causes the constant tension counterbalancinglassembly to move. dancer roll I3 counterclockwisexas viewed in Figure 6. This counterclockwise movement is translated through the mechanism to decrease theV resistance of rheostat |84 in the field circuit of the booster generator, and, therefore, to increase the power supplied to the motors of the tractor Lwheel and capstan of the No. 2r shaving unit.

Dancer roll 23 of the No. 2 shaving unit and dancer roll 33 of the No. 3 shaving unit are associated with mechanisms identical with that just described in connection with dancer roll I3 so that each dancer roll controls the speed of the next shaving unit of the series in response to the speed of the preceding shaving unit as determined by the loop of wire which passes around the dancer roll.

Dancer roll d3 of the No. 4 shaving unitvopcrates through an electrical relay to control the power supplied to the wind-up drum in a manner to be described hereinafter. This electrical relay is used between the No. 4 shaving unit and the wind-up drum because at this point the wirehas been Shaved to a small fraction of its original cross-section and is relatively weak in tensional strength. The wire is shaved s0 thin by the last 'shaving unit that it is not strong enough to 'withstand the counterbalancing effectsof weights sufficiently heavy to move the control shaft of a regulating rheostat and therefore, an electrical relay is inserted which is responsive to the position of the light counterweights of the No, 4 shaving Vunit to operate an electrical torque amplifier which supplies the necessary power to `move the rheostats which control the driving force at the wind-up drum.

A manualV control for positioning and locking dancer rolls, I3, and 33 is shown in- Figure 6 in connection with dancer rollV i3. `A segment gear |83 is keyed to dancer roll shaft |59 intermediate dancer roll arm i5 and. double lever |52. Sometimes it is desirable to relieve the tension in wire W, as for example, to make an adjustment to the wire or to repair a break. Upon ysuch an occasion dancer roll shaft itil may be rotated clockwise, as viewed in. Figure 6, by means or' segment gear |88 through a pinion |93 carried on a pinion shaft |62. A ratchet |922 is keyed to shaft |92 and may be rotated by a loosely mounted lever |96 which carries a pawl is?. Ratchet. itarnay be locked in any position by means of a lever-|98 which carries a stop |98;

Wind-up drum speed controZ Referring to Figure '7, a portion of the control mechanism for controlling the power supplied to the wind-up drum in response to the position of the dancer roll of the No. 4 'shaving unit is illustrated. Figure 8 represents a perspective View tions through alinkZIllI V.to .the segment-Weights 286, 281, and2ll8. .The end of asprocket chain 2li) is secured to the underside of weight 261 and in contact with its curved under surface in a manner calculated to maintain a constant lever arm through weight 261 throughout the various positions taken `by the segment weights. The segment weights are keyed toa roller bearing mounted shaft for swinging rotation after the fashion already described in connection with the segment weights shown in Figure 6.

Sprocket chain 2|0 is led around a sprocket guide 2I2 and upwardly to a bar 2|4 to which it is fastened. From bar 2|4 sprocket chains 2|6 and 2|1 pass upwardly over and around sprockets 220 and 22|, respectively, carried by a shaft 222, and downwardly to a weight 224 suspended therefrom. Sprocket guide 2|2 and Shaft 222 are carried in ball bearings.

The near end of shaft'222 carries a housing 226, shown in greater detail in Figures 9 and 10. A4 contact 225 is solidly mounted upon, but electrically insulated from, the end of shaft 222 within housing 226. Referring to Figure 9, a sprocket 230 is shown on shaft 222 and secured to housing 226. Sprocket-.236 and `housing 226 are freely rotatable upon shaft 222. Within housing 226 an insulating block 228 is shown which carries an insulating element 232, a contact segment 234, and a contact segment 235 (see FigurelO). Contact 225 turns with shaft 222 under the control' of, sprocket chains 2l6 and 2I1. ,Insulating element `232 and `contact segments 234 and 235`turn with housing 226 and sprocket 236 in a manner to be described under the control of a sprocket chain 238 (see Figure '1).v k

Under ideal working conditions dancer roll 43 and dancer roll arm 45 are exactly counterbal'- anced by segment weights 266, 281, and 288and the relatively small tension upon the thinly shaved wire passing around dancer roll 43 is exactly counterbalanced by the relatively light weight 224. With dancer roll 43 and dancer `roll arm 4 5 in close balance with the Isegment weights, the tension upon the wire passing around dancer roll 43 at any time will depend upon the amount of the pull provided by `weight 224. If the speed of the No. 4 shaving unit tends to increase over the speed `at which wire is wound upon the windup drum, weight 224 maintains constant tension vin the wirer by lowering at a rate corresponding to the difference in speeds. In so lowering, shaft 222 is rotated in a clockwise direction, as viewed in Figure 7. Housing 226 and sprocket 236 remain stationary, however, whereupon contact 225 engages with contact segment 234, closing a circuit which applies more power to the wind-up drum in order to counteract the slight difference in speed andrto return dancer roll 43 to its former, or neutral, position. Simultaneously, housing 226 and sprocket23l are rotated clockwise to break the circuit which was ,closed by contact 225 and contact segment 234, in a manner now to be described.

Figure 8 shows'in, its upper left hand corner thev other end of sprocket'chain 238 from that illustrated and described in connection with Figure 7. Chain 236 passes around a sprocket 246 keyed to a countershaft 242 mounted inconventional bearings. Countershaft 242 is driven by a sprocket 256 through a sprocket chain 258 which passes downwardly about a driving sprocket, not shown, mounted upon a shaft 268. Shaft 266 is driven by an electric motor 262 through a speed reducing gear. When shaft 222 (see Figure 7) rotates in a clockwise direction to close the circuit between contact 225 and contact segment 234, electric motor 262 comes into operation to drive shaft 266 in a clockwise direction, as viewed in Figure 8. Clockwise movement of shaft` 266 causes clockwise movement of shaft 242 and, through sprocket chain 238, clockwise movement of housing 226 (see Figure 7) .until the circuit through contact 225 and contact segment 234 is broken.

Counterclockwise movement of shaft 222 makes a circuit through contact 225 and contact segment 235 to initiate operation of motor 262 in the opposite direction to rotate shaft 266 counterclockwise, as viewed in Figure 8. Counterclockwise movement of shaft 260 causes counterclockwise movement of counter-shaft 242 and hence of housing 226 until the circuit made by contact 225 and contact segment 235 is broken. Figure 8 shows rheostats 248 and 254. When shaft 242 is rotated in a clockwise direction a sprocket 244 on shaft 242 causes clockwise movement of a sprocket 241 by means of a sprocket chain 246. Clockwise movement of sprocket 241 causes a reduction in the resistance provided by rheostat 248 in the armature circuit of themotor which drives-V the wind-up drum.` Clockwise movement of shaft 2.42 also causes clockwise movement of a sprocket 250 on shaft 242 which, in turn, causes clockwise movement of a sprocket 253 by means of a sprocket chain252, Clockwise movement of sprocket 253 causes a reduction of the resistance inserted by `rheostat 254 in the field of a booster circuit which provides power to the armature of the motor which drives the wind-up drum. i

Hence, clockwise rotation of shaft 242 provides a decrease `in resistance in, and an increase in power supplied to, the armature circuit of the motor which drives the wind-up drum. With this arrangement, therefore, it is apparent that a slightincrease in the speed of the wire which passes arounddancer roll 43 causesa slight increase in the power applied to the wind-up drum.

This slight increase in power tends to equalize the speed of the wire at the wind-up drum and to position the various counterbalancing means for optimum conditions. v i

Shaft 242 carries a cam 266, and below shaft 242 in position'to be engaged by cam 266, under certain conditions, levers 268 and 210 are positioned. If shaft 242 rotates in a clockwise direction sufficiently far `in response to sucient changes in speed of the wire being shaved, cam 266 'engages lever 268 to operate a mercury switch, which, through conventional relays not shown, stops motor 262. Likewise, counterclockwise movement of shaft 242'a sufficient Vdistance in response to a sufficiently great 'change of speed causes cam 266 to come into engagement with lever 210 to operate a mercury switch which opens the contacts stopping motor 262.

Shaft 242 is provided vwith a manually adjustable friction brake 21| whereby a drag may be imposed against rotation of shaft 242 to eliminate\hunting.

Toward the rear end of shaft 242, as viewed in Figure 8, a sprocket 212 is secured driving a sprocket chain 214. Chain, 214 controls a rheostat in acircuit which positions a pointer on the main control board ofthe plant, which, pointer shows the position `at all times of dancer roll arm 45 so that an operator atthe control board may determine by a lglance at the pointer whether the dancer roll assembly` for the No. 4 shaving unit is operating under the optimum conditions '.Fhe electricaly system The wiring system of the plant is schematically represented in Figures lla and 1lb. Supply lines 33|) and 30| for the fields of the various motors are indicated -across the top of these iigures.' :Supply lines 332 and 333 for the armature circuits of the various motors are indicated across the bottom of these gures. l

Dynamic brake generators X, Y, and Z (see also Figure la) appear in the left-hand portion of Figure lla. Current is supplied to the fields of vthese generators through individual lines including manual rheostats SIS, as indicated. The armatures of these generators are connected to the contacts of double throw switches 3.18, each of which, as shown, is closed to direct a circuit through an adjustable resistance and a normally closed contacter in parallel with the resistance. This contactor opens automatically when the main line switch which supplies power to armature lines 332 and 333 for the driving motors of the plant is closed. The contacter is used to short-circuit the resistance wheny the main line switch isopened to bring the generator to an even stop. vThe control of generators X, Y, and Z is a part of the invention of Crosby Field .and is disclosed and claimed in. his copending application, VledV herewith. Ordinarily one of the generators, or combinations lof them, is driven'by the movement of wireW with the armature circuit closed through the adjustable resistancelrather than across leads to supply lines 32 and 333 so that the` generator is run as a brake to create a tension on wire W. These generators can :be run as motors in the reverse direction, however, to wind back Vslack as, for example, after the repair of a break in theV wire, For a more detailed eX- planation of the feedingV unit, reference should be mayvmore easily be threaded with wire or ad# justed, or so that a break in the wire may be more easily repaired.V

Current is supplied to lines 330 and 3i!!` from a 240 volt D. C,V source. Current is supplied to lines 332 and 333 by a variable voltage generator 3056, indicated at the right in Figure 1lb. Voltage from generator 3.3.3 is controlled through a field rheostat 3.03 which feeds from the 249 volt D. C. lines 333 and 33t. Rheostat 333 is operated by a reversible electric motor driving a 4shaft indicated at 3 i3; By `means of an interlocking control mechanism, not shown, motor `shaft 3Ill always positions rheostat 338 so that when generator 333` is rst connected `across supply lines 392 and 333 it supplies seveny volts. is so controlled that the maximum output into lines 332 and 333 from generator 386 is 260 volts. The control board of the plant is provided with raise and lower buttons for controlling motor shaft .34.0, whereby, if it is desired to raise the voltage .across lines 332-303, the raise but- Rheostat 33,8

stat A3038 until the lower button is released or untila minimum ,of seven volts is reached. A switch is indicated for opening the armature lines 332 and 333 under the control of a master relay Sli. Relay 3M is interconnected with stop buttons throughout the plant and upon the control board so that the lines 332 and 333 may be instantly opened from any one of various convenient locations. Switch 3|2 can be closed only by a start button located on the control board,

When switch 32 is opened, all the motors are brought to an even and immediate stop by virtue of the fact that their fields remain excited from the lines 333 and 3M, whereby they have the effect of being converted into individual generators directing current through the armature lines and across the resistor 333. Resistor 338 is in series with a normally closed contactor, as illustrated. This contacter is held open as long as switch 3l2 is closed. An electrical and mechanical interlock, not shown, requires that this normally closed contacter be opened, and that the normally closed contactors which short circuit switches 3|8 of generators X, Y, and Z also be opened, before switch 3l2 can be closed. The pressing of the single start button first opens these contactors and then closes Lswitch 3I2. By thus converting the various motors into generators operating across resistor 338, all of the motors, in effect, take on a dynamic braking action whenever armature line switch 3|2 is .opened s0 that the `entire plant is brought to an even stop. Every time switch 3| -2 is opened, an interlocking mechanism returns rheostat 308 to the position which gives an output of seven volts from generator 366 into lines 332 and 333 and switch 3I2wcannot again be closed until rheostat 338has been returned bymotor shaft 3H) to the seven volt position.

Motors 26 and 2l, which drive the tractor wheel and capstan, respectively, of the No.2 shaving unit are illustrated at the right-hand side of YFigure lla. Motors 36 and 3l, which drive the tractor wheel and capstan, respectively, of the No. 3 shaving unit and motors 43. and All., which drive the tractor wheel and capstan, respectively, of the No. 4 shaving unit, are indicatedv in the left-hand portion of Figure 11b. The .details `of the circuits for these latter four motors will not be described because they correspond to those of the control system of motors 26. and 2]. Corresponding parts in the No.3,shaving uni-t control have been given the same reference characters as those parts in the No. 2 shaving unit except for the addition of an a. Similarly, correspond ing parts of the No. 4 shaving unit are indicated by identical reference numerals with the addition of a b.

Referring to motors 26 and 21, the el'ds are shown connected in parallel with one another across lines 330 and 3'l. `A variableresistance 324 is indicated in series with the e'ld of motor 2l. The armatures of motors 26 and 21 likewise are in parallel with one another and are provided for connection into supply lines 302 and 303 through the 'armature of a booster generator 325 by means of a reversing switch 326. The field of booster generator 3251s connected through rheostat 83 to lines 3001 and 30H). Normally open contactors 334 and 395 automatically-are closed toV complete the circuit between lines 3D0 and 30017, and lines 33| and 30H), when switch 3l2 is closed. An electrical interlock with switch SI2 assures that contactors 334- and 305- shall open whenever switch 3|2 opens. litheostatelSli, previously described in connection with Figure 6,

with its output under the control of rheostat 254 j (see also Figure 8) as effected through the sprocket indicated at 256. The current flowing through the armature of motor G is also under the control pf rheostat 248 (see also Figure 8) in response to the position of the sprocket indicated at 244.

In the armature circuit of each of the'motors, a load responsive relay L is indicated for opening switch 312 upon an overload therethrough. Each of the amature circuits for the motors X,

Y, Z and 56 also includes a no-load responsive 1 relay N which opens switch 312 upon a break anywhere in the wire .being shaved, since such break wouldrcause a loss of load either at the feeding unit or at the winding unit.

The speed at which the No. 1 shaving unit is to be operated is adjusted through rheostat 320 and moto;1 IS of the No. l shaving unit may, therefore, be called the lead motor. The speeds at which the other motors will be operated` are automatically governed bymeans of the booster generators responding to the wire speedas indicated by the dancer rolls, in the manner described. In the embodiment illustrated the booster generators have a maximum output of about thirty volts. tionships between tractor wheel motor and capstan motor in the Nos. 2, 3 and 4 shavingr units may be adjusted through variable resistances 324, 32'4a, and 324D,

The invention has been illustrated and described in the form which it takes in one plant now in operation. The embodiment illustrated and described, as pointed out above, has made the production of metal wool practical in a more compact plant than any known in the prior art, requiring fewer operators and capable of being run with a higher yield and under better control.

As many embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set.

forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

We claim:

1. In apparatus of the class described wherein metal wool is shaved from wire, the combination with a wire feeding means of t a rst shaving unit comprising a motor-driven tractor wheel and a dancer roll the position of which is responsive to wire speed; second, third and fourth shaving units each comprising a motor-driven tractor wheel, a motor-driven capstan and a dancer roll the position of which is responsive to wire speed; a wind-up unit comprising a motor driven wind-up drum; means for controlling the speed at which the first shaving unit operates; means responsive to the position of the rst dancer roll for controlling the speed at which Y the second shaving unit is operated; means responsive to the position of the second dancer The relative relaru for' `controuing' the speed at which? the vthird f shaving unit operated means" responsii'fe` to the position of the' thirdjdancerroll for contrch` lingthe speed 'at which the fourth shavingunit isoperated; and means responsive to the position ofthe fourth dancer roll for controlling the speed at whichthe wind-up drum is operated.

"2. Apparatus as set forth in claim 1 further characterized by the fact that one of the speedcontrolling means comprises an electrical relay, a motor and a rheostat; said relay including contact means, one of which is moved by movement of an associated dancer roll to complete a circuit through said motor; said motor being arranged to vary the eiTect of said rheostat, and said rheostat being arranged in series with the power supply to the motor-drive of the following unit.

3. In a plant for producing metal wool from a wire including a power driven tractor wheel of a width to receive a plurality of wire loops side by side and around which the wire may be passed, and a plurality of knives positioned adjacent the periphery of the tractor wheel and adapted to shave wool-like metal filaments from the wires of the loops as the tractor wheel rotates to drive the wire past the knives, the combination with said tractor wheel of a friction booster; said friction booster including: a capstan of approximately the same width as the tractor wheel and about which each loop of wire passing about the tractor wheel may also be passed, power supply means for driving said capstan, and means for controlling said power supply means;Y whereby tension in the nights of a wire loop passing about both thetractor wheel and said capstan may be raised or lowered by raising or lowering the power plied to said capstan.

4. In a plant for producing metal wool from a wire including a power driven tractor wheel of supa width to receive a plurality of wire loops side by side and around which the wire may be passed, and a plurality of knives positioned adjacent the periphery of the tractor wheel and adapted to shave wool-like metal filaments from the wires of the loops as the tractor wheel rotates to drive the wire past the knives, the combination with said tractor wheel of a friction booster; said friction booster including: a capstan of approxithe combination including a tractor wheel and a capstan of approximately the same width and adapted to receive a common loop of wire, an

electric motor arranged to drive the tractor wheel, an electric motor arranged to drive the capstan, means for supplying and controlling electric power to said tractor wheel and capstan motors, and means for adjusting the supply of power to said capstan motor with respect to the supply of power to said tractor wheel motor, whereby the power supplied to the capstan motor may be modulated with respect to the power supplied to the tractor wheel motor thereby to raise or lower the pull of the capstan upon the wire.

6. Apparatus as set forth in claim l further characterized by the fact that one of the speed controlling means comprises a multi-position electric relay, a reversible motor operated by said movements of an associated dancer roll to bring 110 portions of said contact means together to close a circuit through said motor and institute a regulating action through said rheostat, and the other of said contact means being responsive to operating movements of said motor to open said motor circuit when a predetermined rheostat regulation has been accomplished.

CROSBY FIELD.

GERALD C. TOOLE. 

